Glossary of Terms Used in In Vitro Fertilization (IVF)
Assisted Hatching: A laboratory technique where the outer shell of the embryo is thinned to facilitate implantation into the uterine wall.
Assisted Reproductive Technology (ART): Medical procedures used primarily to address infertility. This includes procedures like IVF, intracytoplasmic sperm injection (ICSI), and cryopreservation.
Blastocyst Culture: Growing embryos to the blastocyst stage (5-6 days old) for improved implantation chances.
Blastocyst Transfer: Transferring embryos at the blastocyst stage (5-6 days old) for improved implantation chances.
Blastocyst: A stage of embryo development, typically reached five to six days after fertilization, when the embryo is ready for implantation into the uterus. Late-stage embryo with an inner cell mass (developing embryo) and an outer trophectoderm (forms the placenta).
Catheter: A thin tube used for procedures.
Cleavage: Early embryo cell division.
Controlled Ovarian Hyperstimulation (COH): Hormone injections to stimulate egg production.
Conventional insemination: Placing sperm in a dish with eggs for natural fertilization.
Cryopreservation: The process of freezing eggs, sperm, or embryos for use in future ART cycles.
Ectopic Pregnancy: Embryo implanted outside the uterus.
Egg Donation: The process by which a woman donates eggs for purposes of assisted reproduction or biomedical research.
Egg Retrieval: A surgical procedure to collect the eggs from the ovaries.
Embryo Culture: The process of growing embryos in the laboratory after fertilization.
Embryo Transfer: The process of placing an embryo into the uterus of a female with the intent to establish a pregnancy.
Embryo: An early stage of development that follows fertilization of an egg by a sperm.
Endometrial Lining: The lining of the uterus, where the embryo implants.
Endometrium: The lining of the uterus.
Estrogen: A hormone used in some IVF protocols to support the development of the endometrial lining.
Fertility Clinic: A medical clinic that specializes in helping couples and individuals who want to have children but are experiencing fertility issues.
Fertility: The natural capability to conceive children.
Fertility: The natural capability to conceive children.
Follicle Stimulating Hormone (FSH): A hormone given to stimulate the ovaries to produce multiple eggs.
Follicle: A fluid-filled sac in the ovary that contains an immature egg (oocyte).
Follicular Aspiration: Retrieving eggs from the ovaries using ultrasound guidance.
Gestational Carrier: A woman who carries and delivers a child for another person or couple. The gestational carrier has no genetic link to the child.
Gonadotropin-Releasing Hormone (GnRH): A hormone that controls the release of FSH and LH from the pituitary gland.
Gonadotropins: Hormones used to stimulate the ovaries to produce multiple eggs.
Hormonal Assays: Blood tests to measure levels of hormones such as estrogen and progesterone, important for monitoring the progress of IVF treatment.
Human Chorionic Gonadotropin (hCG): A hormone injected to trigger ovulation after follicular development during IVF.
Implantation: The process by which an embryo attaches to the wall of the uterus.
In Vitro Fertilization (IVF): A process of fertilization where an egg is combined with sperm outside the body, in vitro ("in glass").
Incubator: Controlled environment for embryo development.
Insemination: Mixing sperm with eggs to facilitate fertilization.
Intracytoplasmic Sperm Injection (ICSI): Injecting a single sperm directly into an egg for cases of severe male infertility.
Luteal Phase Support: Medications used after embryo transfer to help support the uterine lining and increase the chances of implantation.
Luteinizing Hormone (LH): A hormone involved in triggering ovulation.
Miscarriage: Pregnancy loss after embryo transfer.
Morula: Compact ball of cells formed after several rounds of cleavage.
Multiple Pregnancy: Carrying twins, triplets, or more after embryo transfer.
Oocyte Activation: Initiating the egg's activation process for fertilization.
Oocyte Retrieval: The actual process of collecting eggs.
Oocyte: A mature egg cell.
Ovarian Hyperstimulation Syndrome (OHSS): Excessive fluid buildup in the ovaries after COH.
Ovarian Stimulation: The use of medications to stimulate the ovaries to produce multiple eggs during one menstrual cycle.
Polar Bodies: Small cells expelled from the egg during maturation.
Preimplantation Genetic Diagnosis (PGD): A technique used to identify genetic defects in embryos created through IVF before pregnancy.
Preimplantation Genetic Testing (PGT): A procedure used to test embryos for genetic abnormalities before transferring them to the uterus.
Progesterone: A hormone used to prepare the lining of the uterus for implantation and to support early pregnancy.
Pronucleus: Sperm and egg nuclei before fusion.
Reproductive Endocrinologist: A doctor who specializes in the treatment of disorders related to fertility, menstruation, and menopause.
Semen Analysis: Assesses sperm count, motility, and morphology.
Sperm Donation: The process by which a man donates semen, the fluid containing sperm, to help an individual or a couple conceive a baby.
Sperm Washing: A process in which individual sperm are separated from the semen for use in IVF or intrauterine insemination (IUI).
Sperm: Male reproductive cells.
Surrogacy: An arrangement where a woman (surrogate mother) agrees to bear a child for another person or couple, who will become the child's parent(s) after birth.
Traditional Surrogacy: A form of surrogacy where the surrogate mother is also the egg donor, and therefore genetically related to the child.
Transcervical Catheter: Thin tube inserted through the cervix to place embryos into the uterus.
Transvaginal Ultrasound (TVS): Monitors follicle growth and endometrial thickness.
Transvaginal Ultrasound-Guided Follicular Aspiration: Using ultrasound to guide a needle through the vagina and into the follicles to aspirate eg
Ultrasound Guidance: Ensures accurate embryo placement.
Ultrasound Monitoring: The use of ultrasound to visualize the ovaries and developing follicles during treatment.
Ultrasound: Imaging technique used for monitoring ovulation and follicles.
Zygote: The initial cell formed when a sperm cell unites with an egg cell.
The Developmental Stages of a Human Egg (Oogenesis):
Oogonium Stage: This is the earliest stage where cells that will become eggs are formed. These cells are called oogonia and are created within the ovaries of a female fetus. Oogonia multiply by mitosis and form primary oocytes.
Primary Oocyte Stage: Primary oocytes start meiosis but stop at prophase I during fetal development. They remain in this suspended state until puberty.
Follicular Development: During a woman's reproductive years, some primary oocytes resume meiosis I every menstrual cycle. The primary oocyte, surrounded by layers of cells forming a follicle, grows and matures in the ovary.
Secondary Oocyte and First Polar Body Formation: Meiosis I is completed just before ovulation, forming a secondary oocyte and a small cell called the first polar body. The secondary oocyte immediately starts meiosis II but stops at metaphase II.
Ovulation: The secondary oocyte is released from the ovary during ovulation. If fertilization occurs, meiosis II (MII) will continue.
Fertilization and Ootid Formation: If a sperm cell penetrates the secondary oocyte, meiosis II resumes. The secondary oocyte divides to form an ootid and a second polar body.
Mature Ovum: Finally, the ootid undergoes a period of maturation to become a mature ovum, or egg, capable of being fertilized to form a zygote, the first stage of a new individual.
